JP5760265B2 - Annular seal member - Google Patents

Description

  The present invention relates to an annular seal member used for sealing between a shaft and a shaft hole in a non-return state in a hydraulic control device and a hydraulic device. The non-return state referred to here is a state in which the pressure or the outflow of liquid from one side of the space partitioned by the seal portion is allowed and the outflow from the other side to the one space is prevented.

  As a conventional example of the annular seal member mentioned above, for example, there is one disclosed in Patent Document 1 below. The annular seal member (packing) shown in this document has an annular base portion and a lip portion extending in the axial direction from one end side of the base portion. In addition, a pressure guide path is provided on the outer periphery of the base for guiding the hydraulic pressure in the space defined by the seal portion (the space on the side where pressure accumulation avoidance is required) to the contact portion of the lip with respect to the groove bottom of the seal groove.

  The annular seal member is accommodated in an annular seal groove, and the base portion is compressed in the axial direction so as to be interposed between the shaft and the shaft hole. Then, the seal edge near the free end of the lip portion is brought into close contact with the seal mating surface (the groove bottom of the seal groove).

JP 2008-144784 A

  When the annular seal member disclosed in the above-mentioned Patent Document 1 has an excessive tightening margin due to dimensional variation or the like {when the diameter of the bottom of the seal groove is smaller than the diameter of the base end (base) of the lip portion} In addition, the slit provided as the pressure guiding path due to elastic deformation or creep deformation is deformed and raised near the base end of the lip portion, and the pressure guiding path is closed. As a result, the force that separates the lip portion from the seal counterpart surface (the pressure difference between the partitioned spaces A and B, which is referred to herein as the valve opening pressure) varies, and a stable pressure release function cannot be obtained.

  In addition, if the number of installed pressure guiding paths is increased or the width of the pressure guiding paths (slits) is increased in order to avoid blocking of the pressure guiding paths, the inner diameter side of the annular seal member is uniformly and sufficiently close to the outer periphery of the shaft. The pressure (surface pressure) to be pressed against the surface cannot be obtained, the reliability of the seal is lowered, and the possibility of liquid leakage is increased.

  In the present invention, an annular seal member having a check function can be separated from one surface (space A) to the other space (space B) by separating the lip from the surface to be sealed with a small valve opening pressure even if there is a dimensional variation. The issue is to ensure that the release of pressure is stable.

In order to solve the above-described problems, the present invention provides the following seal members i) to ii) as an annular seal member that seals between a shaft hole and a shaft inserted into the shaft hole.

i) An annular base portion that is compressed in the radial direction and disposed between the shaft hole and the shaft; a hole surface of the shaft hole that is a seal mating surface extending from one end of the base portion; an annular lip of adhering the lip edge hand of an outer peripheral surface, and the convex portion contacting with a tightening margin to the seal mating surface provided to protrude into the sealing mating surface and facing the radial in the direction of the face of the base portion, the surface facing the sealing mating surface before Symbol base, said base and adjacent the other end of the base to the a passage groove provided by Desa extend toward the installation side of the annular lip, the proximal end of the previous SL annular lip Provided in a surface facing the seal mating surface, a recess having a circumferential dimension larger than the groove width of the passage groove, and projecting in a radial direction at a connection portion between the passage groove and the recess, The passage groove and the recess communicate with each other around the abutment. Having a projection causing between.

  In the present invention, a plurality of convex portions are interspersed at intervals in the circumferential direction, and a valley formed between adjacent convex portions in this state is also regarded as the passage groove.

ii) An annular base portion that is compressed in the radial direction and disposed between the shaft hole and the shaft; a hole surface of the shaft hole that is a seal mating surface extending from one end of the base portion and the shaft; An annular lip that closely contacts a lip edge to one of the outer peripheral surfaces of the first protrusion, and a first protrusion that protrudes in a radial direction on a surface of the base that faces the seal mating surface and contacts the seal mating surface with a tightening margin. And a second projecting portion projecting in a radial direction between the first projecting portion and the base end of the annular lip, the second projecting portion projecting in a radial direction, provided on a surface facing the seal mating surface of the base portion, and the seal of the base portion A passage groove provided on the surface facing the mating surface so as to extend from the other end of the base portion toward the installation side of the annular lip, and is formed between the second convex portion and the base end of the annular lip. A recess having a circumferential dimension larger than a groove width of the passage groove; and the passage groove Wherein protrudes radially to the connecting portion between the concave, having a projection causing the communication space of the passage groove and the recess around the self abuts the seal counterface.

  It is preferable that the second convex portion is constituted by a ridge that is continuous in the circumferential direction except for the position of the passage groove.

These annular sealing members are provided in the passage groove in the form in which the protrusion is led from the start end of the passage groove to the intersection of the passage groove and the recess, or in the form of provision in the intersection of the passage groove and the recess. Can be considered.

The concave portion of the annular seal member is preferably an annular concave portion continuous in the circumferential direction, but the object of the invention can be achieved even if the concave portion is divided in the circumferential direction.

In the annular seal member according to the present invention, a projection provided at a connection portion between the passage groove and the concave portion abuts against a seal mating surface, thereby creating a communication space between the passage groove and the concave portion around itself. As a result, even for products with dimensional variations, a pressure introduction space (gap) for applying valve opening pressure to the annular lip is stably secured between the seal mating surface and the passage groove for the pressure introduction space. As a result, the stability of the pressure release function is enhanced.

Further , according to this structure, there is no need to increase the number of passage grooves or increase the groove width of the passage grooves, and the tension force applied to the surface of the annular seal member on the side opposite to the convex portion forming side can be reduced. decrease, Ru can avoid the reduced reliability of the seal by it.

  In addition, when the concave portion is annular, the entire circumferential direction of the annular lip can function as a valve, which contributes to further suppression of variation in valve opening pressure, improved sealing performance of the annular lip, and improved durability.

  In the case where the second convex portion is constituted by a ridge that is continuous in the circumferential direction excluding the position of the passage groove, the variation in each circumferential portion of the shape of the concave portion (pressure introduction space) is suppressed. The contact pressure (surface pressure) of the annular lip against the mating surface is averaged at each part in the circumferential direction, leading to stabilization of the seal.

In the case where the protrusion is provided in the passage groove from the start end of the passage groove to the intersection of the passage groove and the recess, the passage groove can be reliably prevented from being blocked. .

Also, the pre-Symbol protrusions that provided at the intersection of the recess and the passage groove, is never narrowed passage grooves by the projections. Therefore, the width of the passage groove can be narrowed to reduce the variation range of the tightening allowance (that is, the variation region of the compression reaction force) in each circumferential portion of the base, and stabilization of the valve opening pressure can be expected due to this. .

Sectional drawing which shows the 1st form of the reference example of an annular sealing member Sectional drawing which shows an example of use of the annular seal member of FIG. Sectional drawing which shows the 2nd form of the reference example of an annular sealing member Sectional drawing which shows the 3rd form of the reference example of an annular sealing member The top view which shows an example of the annular seal member of this invention The expansion perspective view of the principal part of the cyclic | annular seal member of FIG. The top view which shows the other example of the annular seal member of this invention The expansion perspective view of the principal part of the cyclic | annular sealing member of FIG. The top view which shows the state which biased the protrusion provided in the connection part of a channel groove and a recessed part to the one side of a channel groove The enlarged perspective view of the principal part which shows the modification of the protrusion provided in the connection part of a channel groove and a recessed part

  Embodiments of the annular seal member of the present invention will be described below with reference to FIGS. 1 to 10 of the accompanying drawings. An annular seal member 10 according to the first embodiment shown in FIG. 1 includes an annular base 1, an annular lip 2 extending in an axial direction from one end of the base, a first convex portion 3, and a second convex portion. 4, a plurality of passage grooves 5 and a recess 6 are provided. As the material, rubber having a hardness of about 70 to 80 IRHD is used.

  The base 1 of the annular seal member is inserted into a seal groove formed in one of a shaft hole described later and a shaft inserted into the shaft hole, and is disposed between the hole surface of the shaft hole and the outer peripheral surface of the shaft. Is done.

  The illustrated annular lip 2 is referred to as an outer peripheral lip, and extends obliquely from the outer peripheral portion of one end of the base portion 1 in the axial direction and radially outward, and near the free end. (In the case of the illustrated seal member, it has a lip edge 2a to be brought into close contact with the hole surface of the shaft hole. Depending on the purpose of the seal, an annular lip 7 called an inner peripheral lip may be provided on the inner peripheral side of one end of the base 1.

  The 1st convex part 3 is made to protrude in the radial direction on the surface (it is an outer peripheral surface of the base 1 of the figure) which faces the seal other party surface of the base 1. The outer diameter of the first protrusion 3 in the free state is larger than the diameter of the shaft hole. With this setting, the base 1 is compressed in the radial direction by using the region where the hole diameter is exceeded as a tightening margin, and the outer periphery of the shaft is sealed by pressing the inner peripheral surface of the base against the outer periphery of the shaft. .

  The 2nd convex part 4 is also provided in the surface which protrudes in radial direction and faces the seal other party surface of the base 1. FIG. The second convex portion 4 is disposed between the first convex portion 3 and the base end of the annular lip 2. The height of the second convex portion 4 (height from the bottom of the concave portion 6) was about 0.2 mm in the case of a seal member for an outer peripheral seal of a shaft having a diameter of 7 mm.

  Both the first convex portion 3 and the second convex portion 4 are constituted by ridges that are continuous in the circumferential direction except for the position of the passage groove 5. The convex portion of this shape stabilizes the shape of the concave portion 6, makes the contact surface pressure uniform in each circumferential portion with respect to the axis of the base 1, and makes the contact surface pressure uniform in each circumferential portion of the annular lip with respect to the seal counterpart surface. However, the object of the invention can be achieved even with convex portions of arbitrary shapes (for example, hemispherical, pyramidal, truncated conical, etc.) scattered at intervals in the circumferential direction.

  In addition, the first convex portion 3 and the second convex portion 4 can be easily formed into convex portions as shown in the figure whose convex end side is a convex curved surface, but even if the convex portion has a shape in which the protruding end side is angular in the cross section. There is no problem.

  The passage groove 5 extends from the other end (right end in the figure) of the base portion toward the installation side of the annular lip 2 on the side where the annular lip 2 exists (the outer diameter side of the base portion in the drawing). Is provided. If a plurality of passage grooves 5 are provided at equal intervals in the circumferential direction as shown in the figure, the groove width can be narrowed to reduce the variation range of the tightening allowance in each circumferential portion of the base 1.

  In the case of the shaft outer peripheral seal member having a diameter of 7 mm, the passage groove 5 may have a groove width of about 0.2 to 0.3 mm and a depth of about 0.5 mm.

  The recess 6 is formed between the second protrusion 4 and the base end of the annular lip 2. The recess 6 has a circumferential dimension larger than the groove width of the passage groove 5, and the recess 6 is reliably left in the use state of the annular seal member 10, so that the valve opening pressure against the annular lip 2 is increased. A pressure introducing space (14 in FIG. 2) for causing the pressure to act is formed between the sealing counterpart surface.

  The recess 6 is preferable because the illustrated annular recess allows the entire circumferential area of the annular lip 2 to function as a valve, but it may have a shape that is not continuous in the circumferential direction. Moreover, if the distance from the bottom of this recessed part 6 to a seal other surface is larger than the recessed part 8 between convex parts formed between the 1st convex part 3 and the 2nd convex part 4, as shown in a figure. Preferably, in such a case, the concave portion 6 becomes more difficult to close.

  As shown in FIG. 2, the annular seal member 10 according to the first embodiment configured as described above has a shaft hole 11 provided in a hydraulic device or the like and a shaft hole for the purpose of forming a seal portion having a check function. It is built in between the shaft 12 inserted in.

  In the case of the seal portion of FIG. 2, an annular seal groove 13 is provided on the outer periphery of the shaft 12, and the annular seal member 10 is accommodated in the annular seal groove 13 and interposed between the shaft hole 11 and the shaft 12. The At this time, since the first convex portion 3 has a tightening allowance, the base portion 1 is compressed in the radial direction, and the inner diameter side of the base portion is pressed against the outer periphery of the shaft 12 with a pressing force, so that the space between the outer peripheral surface 12a of the shaft 12 The interface is sealed so as not to leak.

  At the same time, the second convex portion 4 is also compressed in the radial direction, whereby the vicinity of the bottom portion of the concave portion 6 is pushed down radially inward to form the hole surface of the shaft hole 11 (the seal counterpart surface referred to in the present invention). A pressure introducing space 14 is formed between the lip 11a and the annular lip 2 for applying a valve opening pressure.

  The pressure introduction space 14 communicates with the space A via the passage groove 5, and thus, when the pressure in the space A exceeds the specified value, the annular lip 2 is sealed against the seal mating surface due to a pressure difference with the space B. And the valve by the annular lip 2 is opened, and the excessive pressure in the space A is released to the space B side.

  When the pressure difference between the spaces A and B is less than the valve opening pressure, the lip edge 2a of the annular lip 2 is in close contact with the seal counterpart surface. In this state, when the pressure in the space B exceeds the pressure in the space A, the lip edge 2a is strongly pressed by the seal counterpart surface, and therefore no pressure or liquid leaks from the space B to the space A.

  FIG. 3 shows an annular seal member 10 of the second form. In the second embodiment, the annular lip 2, the first convex portion 3, the second convex portion 4, the plurality of passage grooves 5, and the concave portion 6 are provided on the inner diameter side of the annular base portion 1 to form an annular shape. The lip edge 2a of the lip is brought into close contact with the outer peripheral surface of the shaft, which is different from the first embodiment. The action and effect are almost the same as in the first embodiment. In the illustrated second embodiment, an annular seal groove is provided on the hole surface of the shaft hole, and the groove is preferably accommodated in the groove.

FIG. 4 shows an annular seal member 10 according to a third embodiment of the reference example . In this third embodiment, instead of the second convex portion 4 of the first embodiment, the concave portion 6 having a circumferential dimension larger than the groove width of the passage groove 5 and communicating with the passage groove 5 is used as a seal for the base 1. The surface facing the mating surface (the outer peripheral surface in the figure) is provided in a state of being dug down.

  Even in this structure in which a state similar to the state in which the second convex portion 4 pushes the concave portion 6 away from the seal counterpart surface in the first embodiment is created in advance, the concave portion 6 is less likely to be blocked as compared with the conventional product.

  In the third embodiment, even if the radial compression amount of the base 1 increases due to dimensional variations, the amount of separation of the recess from the seal counterpart surface does not change much. On the other hand, in the first embodiment, the larger the amount of compression in the radial direction of the second convex portion 4, the greater the amount of separation of the concave portion 6 from the seal counterpart surface. Therefore, the first form is preferable to the third form in consideration of more stable securing of the pressure introduction space.

Figure 5 shows an example of a ring-shaped sealing member 10 of the present invention. The annular seal member 10 shown in FIG. 5 replaces the second convex portion 4 of the first embodiment of the reference example and abuts against the seal mating surface to create a communication space between the passage groove 5 and the concave portion 6 around itself. The protrusion 9 to be made is provided to project in the radial direction at the connecting portion between the passage groove 5 and the recess 6, and this point is different from the first embodiment. The shape of the protrusion 9 is not particularly limited. Either an elongated strip or a small protrusion as shown in FIG.

  As shown in FIGS. 5 and 6, the protrusion 9 may be provided in the passage groove 5 from the start end of the passage groove 5 to the intersection of the passage groove 5 and the recess 6, or in FIGS. 7 to 10. Thus, it may be provided at the intersection of the passage groove 5 and the recess 6. When the projection 9 is provided at the intersection of the passage groove 5 and the recess 6, the projection 9 may be provided so that the entire projection 9 can be accommodated in the intersection, and most of the projection 9 is accommodated in the intersection. It may be in a state where the portion does not fit.

  Protrusions 9 that are provided in the passage groove 5 from the start end of the passage groove 5 to the intersection of the passage groove 5 and the recess 6 are prevented from being blocked by the protrusion 9 being supported. . In the case of this embodiment, no particular problem arises even when the groove width of the passage groove 5 is expanded to about 0.5 to 1.0 mm in the shaft outer peripheral seal member having a diameter of 7 mm.

  As shown in FIG. 9, the protrusion 9 provided at the intersection of the passage groove 5 and the recess 6 may be disposed not on the center in the width direction of the passage groove but on one side of the passage groove 5. In short, what is necessary is just to arrange | position so that the connection of the channel | path groove | channel 5 and the recessed part 6 may not be prevented. In the case where the protrusion 9 is provided at the intersection of the passage groove 5 and the recess 6, the passage groove 5 is not narrowed by the protrusion 9. For this reason, the width of the passage groove 5 can be narrowed to average the interference in the circumferential portions of the base.

  Although not shown in the drawings, the annular seal member of the present invention may be the first form having the second convex part 4 and the protrusions 9 of the fourth form additionally provided. The effect of preventing clogging of the recesses is more stable.

DESCRIPTION OF SYMBOLS 1 Base 2 Annular lip 2a Lip edge 3 1st convex part 4 2nd convex part 5 Passage groove 6 Recess 7 Annular lip 8 Inter-convex recessed part 9 Protrusion 10 Annular seal member 11 Shaft hole 11a Hole surface 12 Shaft 12a Outer peripheral surface 13 annular seal groove 14 pressure introduction space A, B space

Claims (5)

An annular seal member for sealing between the shaft hole (11) and the shaft (12) inserted into the shaft hole,
An annular base (1) disposed between the shaft hole (11) and the shaft (12) after being compressed in the radial direction
)When,
A hole surface (11a) of the shaft hole that extends in the axial direction from one end of the base portion and serves as a seal counterpart surface.
) And an annular lip (2) for tightly attaching a lip edge to one of the outer peripheral surfaces (12a) of the shaft,
A convex portion (3) provided to project radially from a surface of the base portion (1) facing the seal mating surface and to contact the seal mating surface with a tightening margin;
A channel groove (5) provided on the surface of the base portion (1) facing the seal counterpart surface, extending from the other end of the base portion toward the installation side of the annular lip (2);
The circumferential dimension provided on the surface of the base portion (1) facing the sealing mating surface adjacent to the base end of the annular lip (2) is larger than the groove width of the passage groove (5), and the passage groove ( A recess (6) communicating with 5);
The connecting portion between the passage groove (5) and the concave portion (6) is provided so as to protrude in the radial direction, and is in contact with the seal mating surface to communicate the passage groove (5) and the concave portion (6) around itself. An annular seal member having a projection (9) for creating a space. An annular seal member for sealing between the shaft hole (11) and the shaft (12) inserted into the shaft hole,
An annular base (1) disposed between the shaft hole (11) and the shaft (12) after being compressed in the radial direction
)When,
A hole surface (11a) of the shaft hole that extends in the axial direction from one end of the base portion and serves as a seal counterpart surface.
) And an annular lip (2) for tightly attaching a lip edge to one of the outer peripheral surfaces (12a) of the shaft,
A first protrusion (3) provided to protrude in a radial direction on a surface of the base portion (1) facing the seal mating surface and to contact the seal mating surface with a tightening margin;
A second projecting portion projecting in the radial direction (provided on a surface facing the seal mating surface of the base portion (1) between the first projecting portion (3) and the base end of the annular lip (2) ( 4) and
A channel groove (5) provided on the surface of the base portion (1) facing the seal counterpart surface, extending from the other end of the base portion toward the installation side of the annular lip (2);
A recess (6) having a circumferential dimension formed between the second protrusion (4) and the base end of the annular lip (2) larger than the groove width of the passage groove (5);
A connecting portion between the passage groove (5) and the recess (6) is provided so as to protrude in the radial direction, abuts against the seal mating surface, and surrounds the passage groove (5) and the recess (6). An annular seal member having a projection (9) for creating a communication space. Said projection (9), said passage groove (5) according to claim 1 or 2 provided from the beginning to the passage groove (5) and said passage groove (5) in said brought to the intersection of the recess (6) of An annular seal member as described in 1. The said protrusion (9) was provided in the cross | intersection part of the said channel groove (5) and the said recessed part (6) or
Annular seal member according to 2. The annular seal member according to any one of claims 1 to 4 , wherein the recess (6) is an annular recess that is continuous in a circumferential direction.

Images